LG Chem Ltd. (Seoul, South Korea) announced that a high-altitude long-endurance solar-powered unmanned vehicle (EAV-3) developed by Korea Aerospace Research Institute has successfully finished flight testing in the environment of the stratosphere using a unique lithium-sulfur battery.
EAV-3 is a small aircraft which can fly in the stratospheric altitude of 12km or higher for a long period of time using solar energy and batteries. It charges energy using a solar cell placed on the top of the wing. During the daytime, it flies utilizing a solar cell and battery power as a source of energy and during the night time, it utilizes battery power charged during the day time. It has wings of 20m long and a body of 9m long.
On 30 August, LG Chem loaded a lithium-sulfur battery on EAV-3 at the Aviation Center of Korea Aerospace Research Institute in Goheung and conducted flight testing approximately for 13 hours. LG Chem is the first company in Korea which conducted flight testing using a lithium-sulfur battery.
EAV-3 flew in the altitude of 22kms, which is unprecedented for a domestic unmanned aircraft, and achieved a new record of flying at the highest attitude in Korea. Also, it flew for 7 hours out of a total of 13 flight hours with a stable output in the stratospheric altitude of 12-22km where a general aircraft cannot fly.
This fight testing is highly significant as it confirmed a stable charge/discharge function of a lithium-sulfur battery, the next generation battery in the extreme environment of the stratosphere with a low temperature of 70 degrees below zero and atmospheric pressure of 1/25 of one at ground level, which is close to a vacuum state.
A lithium-sulfur battery is one of the next-generation batteries that will potentially replace a lithium-ion battery, and its energy density is 1.5 times higher than the existing lithium-ion battery, which has a high energy density per weight, as it uses lightweight materials such as sulfur and carbon compounds for anode materials and lithium metal, etc. for cathode materials. The merit of the lithium-sulfur battery is that it is lighter and more competitive in terms of price compared to existing lithium-ion batteries, as it does not use rare metals.
For 1.5 years, LG Chem Future Technology Research Center’s Innovative Battery Project Team has conducted research on the development of a lithium-sulfur battery in the low temperature and atmospheric pressure by creating the extreme environment similar to the stratosphere, and could successfully complete this flight testing based on such research.
LG Chem plans to demonstrate a long-endurance flight that lasts more than a number of days by producing additional trial products of lithium-sulfur batteries in the future. Moreover, it plans to mass-produce a lithium-sulfur battery that has an energy density more than twice that of the present lithium-ion battery after 2025.
Kisu Ro, the CTO/President of LG Chem, mentioned “LG Chem has proved that it has the world’s best technology in the sector of the next generation battery with a high energy density from this flight testing” and “it will consolidate its position as the leading firm in the global battery market by focusing on research and development of the next generation battery sector.”